Patients who undergo a common treatment for prostate cancer may be at risk for heart problems, according to a new study announced on Tuesday.

The information revealed at a joint meeting of the European Cancer Organization and the European Society for Medical Oncology in Berlin may cause doctors to rethink prescribing hormone treatment to men with cancer.

"What we can do with these results is to raise a flag with hormone treatments," said Mieke Van Hemelrijck, a cancer epidemiologist at King's College in London and the study's lead researcher.

The research found that prostate cancer patients had a 28 percent higher chance of having a fatal heart attack after undergoing the hormone treatment.

"There is no definitive evidence, though the risk of heart problems is definitely something doctors should consider when prescribing hormone treatment," said Michael Thun, a vice president emeritus at the American Cancer Society.

Prostate cancer is the second-most common cancer in men and more than 670,000 are diagnosed around the world every year.